1. Field of the Invention
The present invention relates to an image pickup apparatus, which picks up an image of a surrounding area of a vehicle. More specifically, the present invention relates to an apparatus for performing the image pickup of an area surrounding a vehicle by irradiating an invisible light, such as light of infrared region from near infrared region.
2. Description of the Related Art
In the vehicle, conventionally, a headlight for securing the visibility of a driver is provided for achieving the safe driving. When traveling the vehicle under low visibility, such as night or fog, just use of the headlight is not enough to secure the visibility for achieving the safe driving
An image pickup apparatus using an infrared light has been developed for supplying the better visibility to a driver driving a vehicle at night, etc.
In the image pickup apparatus, the existence of obstacles, such as vehicle, animals, and humans, which are presenting in the area not covered by the headlight, is detected by picking up the far-inflated light emitted from obstacles.
A technique, in which the image picked by the image pickup apparatus is displayed on the windshield using a virtual display apparatus, has also been developed as one of means for notifying the existence of the obstacles to a driver.
In the image pickup apparatus, there has been developed the technique, in which the infrared camera is adopted, for achieving the certain image pickup of obstacles existing in the surrounding area. In this infrared camera, the image pickup of obstacle is achieved by detecting the reflected infrared light, which is irradiated from the infrared light emitter and is reflected by the obstacles.
When the vehicle equipping the infrared light emitter is traveling on the road adopting the system of driving on the side of the road facing oncoming traffic, the same image pickup apparatus may be equipped in the oncoming vehicle. In that occasion, if infrared light is irradiated from the oncoming vehicle and is received by the infrared camera equipped in the vehicle, the image obtained by the infrared camera equipped in the vehicle on driving is engulfed in a uniformly white glow. Thus, the image pickup is prevented and a driver cannot identify the presence of the obstacles. This phenomenon is known as “whiteout phenomenon”.
Therefore, the image pickup apparatus, which can achieve the image pickup of the surrounding area by receiving the reflected light, which is irradiated from the infrared light emitter of the vehicle and is reflected by the obstacles, has been required.